Skip to main content

Full text of "Text Book Of Mechanical Engineering"

See other formats


8;8

Appendix II.

P. 594. Dryness of Steam.  The finding of dryness
value from indicator diagram has already been shewn at p. 764.
Professor Carpenter plots a further curve beneath the expansion
line to represent the fractions thus obtained, and calls this the
1 quality' curve of the steam. It appears that condensation con-
tinues after cut-off A, Fig. 838, till re-evaporation is reached at B,

. 838.

while the final dryness c is often higher than A. To measure the
condensation due to cylinder walls we must know the original
condition of the steam. Several methods are used, but Carpen-
ter's apparatus, Fig. 839, is probably simplest, while being very

accurate. Steam passes from the pipe A into a jacketed separator
B, where all the moisture is deposited. Continuing to the Avater
vessel c, the dry steam is there condensed, and the graduations